El Cubo is Endeavour’s third and potentially largest mine, located six kilometres southeast of the city of Guanajuato in the state of Guanajuato. Access is by municipal road and infrastructure includes the state power grid, and local labour, supplies and services in the city of Guanajuato. The property covers approximately 8,150 hectares in this second largest historic silver mining district in Mexico.

In 2017, El Cubo produced 1.9 million ounces of silver and 21,357 ounces of gold, totaling 3.5 million ounces of silver equivalent. Silver production met guidance notwhitstanding slightly lower throughput and silver recovery. Gold production was below guidance due to lower thoughput and gold grades.